Melatonin improves rate of monospermic fertilization and early embryo development in a bovine IVF system

Abstract

The developmental competence of male and female gametes is frequently reduced under in vitro conditions, mainly due to oxidative stress during handling. The amino-acid derived hormone melatonin has emerged as a potent non-enzymatic antioxidant in many biological systems. The goal of the present study was to evaluate the effects of melatonin on post-thaw sperm quality, fertilizing ability, and embryo development and competence in vitro after in vitro fertilization. Frozen-thawed bovine spermatozoa were incubated either in the presence of 10−11 M melatonin (MT), or its solvent (ethanol; Sham-Control), or plain Tyrode’s Albumin Lactate Pyruvate medium (TALP, Control). Computer-Assisted Sperm Analysis (CASA) and flow cytometry data after 30 min, 120 min, and 180 min incubation did not reveal any significant effects of melatonin on average motility parameters, sperm subpopulation structure as determined by hierarchical cluster, or on the percentage of viable, acrosome intact sperm, or viable sperm with active mitochondria. Nevertheless, in vitro matured cumulus-oocyte-complexes fertilized with spermatozoa which had been preincubated with 10−11 M melatonin (MT-Sperm) showed higher (P < 0.01) rates of monospermic fertilization, reduced (P < 0.05) polyspermy and enhanced (P < 0.05) embryo development compared to the Control group. Moreover, the relative abundance of MAPK13 in the in vitro-derived blastocysts was greater (P < 0.05) than observed in the Control group. In conclusion, adding melatonin to the sperm-preparation protocol for bovine IVF improved proper fertilization and enhanced embryonic development and competence in vitro.

Exogenous Melatonin in the Culture Medium Does Not Affect the Development of In Vivo-Derived Pig Embryos but Substantially Improves the Quality of In Vitro-Produced Embryos

“…Most studies indicating a positive effect of melatonin during maturation used parthenogenetic porcine oocytes [ 21 , 22 , 24 , 27 , 28 , 52 ], which are more sensitive to oxidative stress than the IVF oocytes [ 64 ]. In other species, such as cattle, the accumulating evidence that the addition of melatonin to the maturation medium is beneficial for the developmental competence of oocytes fertilized in vitro, although not always demonstrated [ 65 , 66 , 67 , 68 ], has encouraged researchers to use this antioxidant during the maturation of bovine oocytes [ 54 , 55 , 56 , 57 , 58 , 59 , 69 , 70 , 71 ]. All these findings suggest that, in addition to the source of the embryos, melatonin added to the IVM medium may function differently between species due to differences in the incubation times, chemical composition, and supplementation of media [ 72 ].…”

Comparative developmental competence of in vitro embryos recovered from Bali cattle with normal and poor sperm motility

“…High polyspermy is also a challenging issue in in vitro embryo production in pigs [57], whereas in bovine in vitro fertilization, high polyspermy is considered a less common problem with an unclear etiology [58]. Despite being regulated by the oocyte [59], strategies implemented at the sperm level have successfully reduced the occurrence of polyspermy [60]. To the best of our knowledge, this is the first study to report that the ≥70% sperm motility group was better at penetrating the oocyte in vitro than the ≤70% sperm motility group.…”

Current understanding of the pathogenesis of placenta accreta spectrum disorder with focus on mitochondrial function

“…MAPK13 inhibits autophagy, mitophagy, and apoptosis through mTOR activation [55]. Bioinformatics analysis of differentially expressed genes in placental cells cultured in vitro from PE and normal pregnancies suggests that MAPK13 may be one of the candidate genes associated with PE [56].…”